The theory of relativity in words of four letters or less

http://www.muppetlabs.com/~breadbox/txt/al.html

by gjm11 • 13 years ago

228 126 13 years ago

muppetlabs.com

haliax• 13 years ago

This is phenomenal, does anyone have sources of more physics concepts explained simply?

Scott Aaronson's Quantum Physics is one: http://www.scottaaronson.com/democritus/lec9.html

chengsun• 13 years ago

Obligatory xkcd: http://xkcd.com/1133/

saraid216• 13 years ago

I want to point out that xkcd's criteria for usable words is a lot better than "four letters or less". There are some really obscure, yet very dense words out there.

darxius• 13 years ago

I found that four letters added some ambiguity and some uneeded complexity. Maybe 5 or even 6 letters?

Still, this is a great intro to relativity and it was a fun read. Also a cool literary feat.

buo4• 13 years ago

About the cool literary feat: I'm wondering if there are languages other than English in which it'd be possible to write something like this. I speak Spanish and French and I'm sure it's impossible in both -- they just don't have enough short words.

hkmurakami• 13 years ago

Probably Chinese and Japanese since Chinese characters have such high information density, but non-Western languages might defeat the purpose of the experiment.

dnautics• 13 years ago

I find the fuzzing of proper names gets annoying, and it would be better if the rule were relaxed for proper names.

shardling8• 13 years ago

Also, a quick google serach indicates that "Ike" is a more common nickname than "Izzy". (And that if Newton had any nicknames in his time, none seem to have survived.)

alexdowad3• 13 years ago

Personally, I found the abbreviated names made the piece even more hilariously irreverent than it already was. "Izzy" for Isaac Newton? Makes him sound like an 1980's heavy metal star or something.

shardling8• 13 years ago

>Say you woke up one day and your bed was gone. Your room, too. Gone. It's all gone. You wake up in an inky void. Not even a star. Okay, yes, it's a dumb idea, but just go with it. Now say you want to know if you move or not. Are you held fast in one spot? Or do you, say, list off to the left some? What I want to ask you is: Can you find out? Hell no. You can see that, sure. You don't need me to tell you. To move, you have to move to or away from ... well, from what? You'd have to say that you don't even get to use a word like "move" when you are the only body in that void.

This is not as self-evident as the author believes.

1. Having taught a great many college level physics students, they have trouble grasping this.

2. More importantly, there's a reason people pursued the theory of the aether for so long -- you have to actually do the fucking experiments to show that there's no absolute reference frame you could be said to be moving in. Thinking that you can deduce physical facts about the universe a priori is the opposite of science.

e: Suddenly remembered a Feynman bit from Lectures where he talks about exactly the attitude of treating this is somehow obvious: http://www.sciencechatforum.com/viewtopic.php?f=10&t=207...

Dylan1680710• 13 years ago

Not only is the point not-self-evident, the analogy is fundamentally flawed. You may not have an absolute speed but you can accelerate. If you really want a reference frame to compare to, you can use the one you started in before leaving.

Edit: sorry, changed wording while being replied to

buo4• 13 years ago

Without a reference frame, what experiment can you perform that would tell you that you're accelerating?

shardling8• 13 years ago

> If you really want a reference frame to compare to, you can use the one you started in before leaving.

Nah, the analogy is fine there -- you "wake up" in a new reference frame, and weren't able to make any measurements to compare it to your old one. Whether you can measure your motion against the old reference frame starting from this situation is actually the question!

oskarth• 13 years ago

I don't understand. What would the alternative be? If the answer to "can you find out" is "yes", then how?

shardling8• 13 years ago

The alternative is that there's some fundamental reference frame. The obvious example is the theory of the aether I alluded to: light would propagate in different speeds in different reference frames.

More generally, you can't know that the laws of physics are the same in all reference frames until you actually do the experiments. If you think otherwise, you underestimate nature's ability to confound human intuition! A good example is is parity, which you'd think would be a good symmetry of nature, but is actually violated by some interactions: http://en.wikipedia.org/wiki/Parity_violation#Parity_violati...

Cushman8• 13 years ago

Exactly my thought reading that. That question, "Can you find out? Hell no," is relativity in a nutshell. If you really grasp what that means, the whole deal from simultaneity to time dilation to curved spacetime all falls out more or less intuitively. (Of course it was harder to work out the first time :P)

Most people implicitly believe that there must be some privileged reference frame, if not mine necessarily than at least one very close to mine, and for good reason. (I'd go so far as to say that most people believe explicitly that there is a privileged reference frame, and that it is an intelligent agent called God, but leave that alone for now.) Even if they do get past this statement with a, "Uh, okay, I guess so..." they probably have not actually adjusted their entire world view to account for that powerful fact, and if they seem to understand what you have told them it is likely that they have simply memorized the right answer.

Not that there's anything wrong with trying.

ars13• 13 years ago

> I'd go so far as to say that most people believe explicitly that there is a privileged reference frame, and that it is an intelligent agent called God

????? Why do you assume God is a physical being inside the universe? (Do people really think that?) God created the universe - God is outside it. Like God is the computer and the universe is the program.

God isn't at rest/not at rest. The concept doesn't even apply.

jules3• 13 years ago

> That question, "Can you find out? Hell no," is relativity in a nutshell. If you really grasp what that means, the whole deal from simultaneity to time dilation to curved spacetime all falls out more or less intuitively. (Of course it was harder to work out the first time :P)

You cannot deduce relativity from the knowledge that you can't find out whether you're moving. In Newtonian physics you can't find out whether you're moving either. The essential ingredient is that the speed of light is the same in all reference frames. Furthermore curved spacetime is by no means trivial; that's general relativity. It took Einstein himself 10 additional years before he got from special to general relativity, and more still to really develop it.

ambiate• 13 years ago

I use the void concept to explain my absurdity. I usually fall back on explaining the thought process that follows awakening in a void. The loss of identity, speech, motion, etc. Now, I wish I had taken a physics class.

jbattle• 13 years ago

This got me thinking. If you are floating along in a void, and float past a virtual particle - you can legitimately say you are moving (of course you could instead say the virtual particle is moving).

Assume now the virtual particle winks out of existence. Have you suddenly stopped moving? Were you wrong/incorrect somehow to have chosen the particle as the rest frame? Has conservation of (your) momentum just been violated?

Cushman8• 13 years ago

I'm no physicist, but my understanding is that observing a virtual particle is a contradiction in terms.

breadbox12• 13 years ago

What I was trying to express by "inky void, not even a star" was that the void didn't even include anything resembling an aether. "You are the only body in that void" is meant to include non-material bodies. All this passage is trying to establish is that in order to distinguish constant motion from absolute stillness, there has to be something else to measure against. Whether or not our universe contains something that can serve as an absolute frame of reference is not the point -- yet.

So yes, it really is meant to be talking about a self-evident fact (once you think about it).

But you're right; I'm not a physics teacher. I'm willing to concede that I underestimated the potential stickiness of this point, and/or that I failed to overcome my handicap in expressing this point.

jules3• 13 years ago

It's only obvious because that's what you were taught. Aristotle thought that a moving body would come to a halt by itself, unless you keep pushing it. He thought that this was a law of physics. This didn't require any aether or other substance. It was almost 2000 years later that Galilei came with the idea bodies set in motion will remain in motion, and that the fact that they usually stop was solely the result of friction. But even then it is not clear that there isn't some other method by which you can find out your absolute velocity. It was only in 1887 that the Michelson-Morley experiment showed that you can't do that with light! So this is not a triviality that can be deduced by logical reasoning, it's an experimental result of physics.

This makes you wonder which falsehoods we currently take for granted, that later generations can't even fathom anymore.

tocomment• 13 years ago

What if there were two bodies instead of one and they were 1 light year apart. What would motion be like then?

Jun8• 13 years ago

"Make things as simple as possible, but not any simpler" - Einstein. His own book from Dover is an excellent way to get started.

jneal• 13 years ago

This is cool. I felt I had to keep my note the same. A very neat idea I'd say. Wish it was more easy to read. Very cool!

205guy• 13 years ago

I see what you did here. I had the same idea, but you beat me to it.

nlh• 13 years ago

Interesting read and I like the concept, but I think the 4-letter rule added an arbitrary constraint that didn't necessarily make it easier to read or understand.

If the idea was "explain relativity simply" then it could have been done better -- word complexity (ie "reading level") is a better measure than outright word length.

If the idea was simply to see if it could be done with 4-letter words, well, mission accomplished :)

breadbox12• 13 years ago

It was in fact the latter.

(I was inspired in part by Douglas Hofstadter, who did something similar on a smaller scale in "Le Ton Beau de Marot".)

derekp7• 13 years ago

Sounds very similar to Guy Steel's "Growing a Language" talk. His constraint was to not use any word greater than one syllable unless it is defined by either one-syllable words, or other words that had been previously defined.

daviddaviddavid• 13 years ago

Wow. I was sure this was inspired by George Boolos' great "Godel's Second Incompleteness Theorem Explained in Words of One Syllable".

http://www2.kenyon.edu/Depts/Math/Milnikel/boolos-godel.pdf

I wonder if Hofstadter was inspired by Boolos?

ArekDymalski• 13 years ago

I think it would be easier to read without all these colloquial bits "like, you know, heck, get over it". Anyway it's impressive effort.

breadbox12• 13 years ago

Those bits are my favorite parts!

heyitsnick• 13 years ago

http://en.wikipedia.org/wiki/Constrained_writing

biot• 13 years ago

Now who can describe the theory of relativity in only four words?

breadbox12• 13 years ago

Everything's relative except c.

Best I could do.

carlob• 13 years ago

This reminds me of 'Gödel's Second Incompleteness Theorem Explained in Words of One Syllable'

https://news.ycombinator.com/item?id=4197284

dpritchett2• 13 years ago

The Up-Goer Five Text Editor is a pretty great resource with similar constraints: "Can you describe a topic using only the thousand most common English words?"

The results in their Hall of Fame are fascinating. It's inspired by the xkcd linked elsewhere in this thread.

http://splasho.com/upgoer5/halloffame.php

wbhart• 13 years ago

Age restricted as inappropriate by UK filters, presumably because it contains "four letter words". Great one O2. Nothing like restricting access by our kids to educational material.

aendruk• 13 years ago

It may be qualifying "she's on her ass" as inappropriate.

whatgoodisaroad• 13 years ago

Am I being pedantic? That really should be four letters or fewer.

pit• 13 years ago

Maybe he means "The theory of relativity in words of four letters or less [than the theory of relativity]" -- i.e., it is an _incomplete_ explanation -- which some of the people on this page seem to agree with. Seriously, I thought this was extremely clever, and the short, clipped style reminds me of Hemingway or Mamet.

breadbox12• 13 years ago

Yes to both.

3minus1• 13 years ago

You don't always use "fewer" when talking about discrete units. For example, you say "less than 5 minutes ago". The same goes for measurements of length (less than 3 meters). I think "less" works here because letters is a measurement of length.

trebor• 13 years ago

I found the article hard to read because of the word length. It created a strange, artificial rhythm to the text that drove me to distraction.

boburhedRAGTOP2• 13 years ago

I know I'm dumb, but can someone explain this part?

"Dana sees each rock at the same time, but Bert sees one rock and then sees the next rock."

How would anyone's movement, or lack of it, affect their perception of whether the rocks landed at the same time or not?

breadbox12• 13 years ago

You're not dumb. It's a subtle point, otherwise special relativity wouldn't have been necessary to invent. (You may find it worthwhile to read a more normal article on special relativity -- it's much easier to understand than general relativity.)

The two rocks land just as Bert and Dana are closest to each other. The two rocks are equally distant from that point. But as the light propagates towards them, Bert continues to move towards the light from the impact ahead of him, and away from the impact behind him. Thus he will see the light from the former impact before the latter.

(The traditional thought experiment is described in terms of trains and lightning, instead of buses and moon rocks. If you do a web search for that plus "special relativity", you should find plenty of descriptions that are closer to the original.)

gjm11• 13 years ago

The rays that come from each rock move only so fast. They take time to get from the rock to Dana or Bert. And it is only by when those rays get to Dana or Bert that they can say if they were at the same time, or one and then the next.

Now. Bert is on the bus. It goes, let us say, from west to east on the road. Bert is half way from the west rock to the east rock when each rock hits land -- but he is on the move, and when the rays from the east rock hit his eyes he has gone some way east. The rays from the west rock have not yet got to him. Then, just a tad more time, and the rays from the west rock get to Bert's eyes.

But Dana does not move. She sits by the road. The rays from the west rock and the east rock hit her at the same time: each rock is, say, a yard from her, one west and one east.

So Dana sits and does not move; she sees the rays from each rock at the same time. Bert is on the bus, and goes from west to east; he sees the rays from the east rock and then the rays from the west rock.

And all that is fine. They both know that Dana does not move and Bert does. So they will say that each rock hit at the same time, for Dana (who did not move) saw them hit at the same time.

But (and this is the bit that may fry your mind) we can just as well say that Bert does not move and Dana does move! And then we will have to say that the east rock hit and then the west rock! How can that be?

We must say, even if you find it odd, that "did the east rock hit, then the west? or the west, then the east? or both at once?" just goes one way for Dana and not that way for Bert. Just like "is this rock to the east or to the west?" may not go the same way for both, if they are not at the same site.

(You are not dumb. This is hard. It took Al to work it out!)

breadbox12• 13 years ago

Yes, you have the idea. You put down just a word or two, no more. But then you add to it, and then some more, and then the next you know, you have a page full of such text. It can be hard to stop once you get into it!

boburhedRAGTOP2• 13 years ago

Thanks to the both of you for taking the time to answer! Makes a lot more sense!

I feel relatively smarter now

Avshalom• 13 years ago

As an explanation it's only mediocre, but it was a lovely poetic read. It felt on the verge of lyrical the entire time.

elliptic• 13 years ago

There's an amusing though mean-spirited article of Paul Samuelson's purporting to debunk the use of the Kelly Criterion - [url]www-stat.wharton.upenn.edu/~steele/Courses/434F2005/Context/Kelly%20Resources/Samuelson1979.pdf[/url] (pdf). All the words are one syllable. I find the title rather poetic - "Why we should not make mean log of wealth big though years to act are long".

GhotiFish2• 13 years ago

I made a word cloud of this

I removed "and", "you", "the", "that", "a", and "to" as those were just a bit TOO big.

http://i.imgur.com/77V6OvQ.png

breadbox12• 13 years ago

What a cool pic. I'm glad that you made it and put the link here. I want to hang it up on my wall!

Raphael• 13 years ago

Al?

GhotiFish2• 13 years ago

ALbert Einstein. I think.

Mz• 13 years ago

Reminds me of the story behind "The Cat in the Hat."

"In May 1954, Life magazine published a report on illiteracy among school children, which concluded that children were not learning to read because their books were boring. Accordingly, William Ellsworth Spaulding, the director of the education division at Houghton Mifflin who later became its Chairman, compiled a list of 348 words he felt were important for first-graders to recognize and asked Geisel to cut the list to 250 words and write a book using only those words. [33] Spaulding challenged Geisel to "bring back a book children can't put down." [34] Nine months later, Geisel, using 236 of the words given to him, completed The Cat in the Hat. It retained the drawing style, verse rhythms, and all the imaginative power of Geisel's earlier works, but because of its simplified vocabulary, it could be read by beginning readers."

From: http://en.m.wikipedia.org/wiki/Dr._Seuss

wfn• 13 years ago

I've stumbled upon Brian's website before and have enjoyed many a writeup, including this one.

I recall particularly enjoying `A Monovocalic Sonnet on Dante's "Inferno"` (http://www.muppetlabs.com/~breadbox/txt/infirni.html) - the essence/joy being in the Notes section: http://www.muppetlabs.com/~breadbox/txt/infirni-notes.html - it's so random and intense - a true hacker spirit I say :)

maeon3• 13 years ago

This article is exactly what I needed, I've been trying to understand the unification of Gravity, Inertia and Centrifugal force for years now, couldn't fathom it, now I can.

The best I can describe it is: "Matter is like water through a drain", I wrote a post with my consolation of how the three can be seen as one:

http://sentientmachine.blogspot.com/2013/05/matter-is-like-w...

jvdh• 13 years ago

Looking at the page full of short words, the whole text just looks very weird, strange and sometimes just distracting. I never knew that I looked over the page so much as I was reading.

pieguy• 13 years ago

There are many interesting pages on this site. The brainfk and Intercal resources are a fun read, also the tiny executables. The Tile World downloads are a bit out-of-date though.

d0m• 13 years ago

I'd prefer "The theory of relativity explained to four years old".. the "four letters or less", although funny, makes it harder to grasp IMHO.

prawn• 13 years ago

I wonder if something like this might be useful if added to Wikipedia's Simple English version of the Theory of Relativity page? That page seems a bit underdone right now.

https://simple.wikipedia.org/wiki/Theory_of_relativity

pjdorrell• 13 years ago

Any one of us can work out x by x plus y by y plus z by z less c by t by t where x and y and z and t are each part of how to get from one "here and now" to a 2nd "here and now". I can try to tell you what c is or we can just say that it is one (i.e. c by t by t is just t by t). And the math that we do will work out the same if I work it out from what I see or if you work it out from what you see, even if I do not move at the same rate as you.

Nilzor• 13 years ago

Why?

The theory of relativity in words of four letters or less

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